I think it is worth suggesting that in game gold should be capable of converting into runes, and/ or be tradeable between all game modes (runes would not be allowed to be converted to gold. Although it would be enjoyable if other game modes could make it possible to build my decks).
This not just gives players more incentive to enjoy the game modes with customization they enjoy, but it would also make a common interest between the games.
I’ve always been bothered by how Battlegrounds (and also Mercenaries) felt like it was separate from Hearthstone all together. On top of that Battlegrounds doesn’t give me anything to improve on the core game. The same also go for Mercenaries. If they had something as simple as a currency between them if would make the tavern feel a bit more interconnected (working in the same universe? All parts of one whole?)
I do not doubt the reason why I feel this way is because I played Hearthstone before these modes existed and when they came out I fully expected they would give me Rewards that would build my deck and give me unique things jus as the solo Adventures did.
Thought for the think tank.